|Inventor of the first U.S. ETF
Nate Most was an industry executive who invented the first U.S. ETF, the SPDR S&P 500 ETF (SPY). He died in 2004, at the age of 90. He had most recently been a board member on the iShares Trust at Barclays Global Investors. 
Before starting his long career in finance, Most worked as a physicist and engineer specializing in acoustics for the U.S. Navy during World War II. He later traded and managed international commodities at the Pacific Commodities Exchange.
He joined the American Stock Exchange in 1976 and worked in new product development in Amex's derivatives business.
In the mid 1980s he came up with the idea of mutual funds that would trade like stocks. According to an article in MarketWatch, he brought the idea to John Bogle, then head of the Vanguard Group. Bogle was thought to dislike ETFs because traders moving in and out of the funds would drive up costs. Their discussion led Most to consider a product where traders did not go in and out of the fund, and that led him to create and develop the SPDR ETFs, which was launched on Amex in 1993 with State Street Advisors as the portfolio manager. There are now 149 ETFs trading in the U.S., according to the Investment Company Institute.
Most also designed an arbitrage mechanism that keeps the price of an individual ETF share in line with the net asset value of the underlying portfolio. This feature prevents the premiums and discounts often seen in closed-end funds.
Most never received any royalties for the financial product he invented.
- ETF inventor Nate Most dies at 90. MarketWatch.